'pentylamine' originates from English, specifically the combination of 'pentyl' (from 'pentane', a five-carbon alkane) and 'amine' (from ammonia derivatives), where 'pentyl' refers to a five-carbon chain and 'amine' refers to a compound derived from ammonia.

'pentylamine' was formed in modern chemistry by combining the names of its structural components, 'pentyl' and 'amine', to describe its molecular structure.

Initially, it meant 'an amine with a pentyl group', and this meaning has remained the same in modern usage.